Making a magnetic tool holder

[Vern2]

Looking at mounting 3 - 1" magnets into aluminum. I have a small mill/Drill and a 6" rotary table. Here is my home shop drawing.



Was thinking I may cut the holes with my largest end mill (3/4") to cut the round magnetics holes.

The three smaller holes are for guide pins.

Any help would be appreciated, with how I can setup rotary table for milling. The 3/4" end mill needs to be off set to create the six holes. Thought I would mill both aluminum parts. one with magnetics the other with steel plugs.
Thank you,

[GlennW]

Hello Vern,

Start by centering the rotary table under the spindle. There are various methods depending on your table. Some have a machined hole in the center that you could sweep with a spindle held indicator.

Once you get the table centered under the spindle, zero both handwheels.

Now figure out just where you want the holes for the magnets and plugs and mark the location on the part. It doesn't sound like a really critical location as far as accuracy as you just meed the magnets to meet the plugs. Place a pointer or something similar in the spindle and then locate the part on the rotary table to where the spindle is over the hole location and clamp the part to the rotary table.

Now with the end mill in the spindle, select either the X or Y axis and move out from the center .100" and lock the both the X and Y axis. Now you can plunge down a bit and start rotating the table. Since the end mill is .750" diameter, and you offset .100", you will be cutting pretty close to a .950" diameter circle. Keep plunging and rotating until you get to the depth you want and then check the diameter of the hole. If it is .950", you will need to move out another .025" in order to get to a 1" hole. .025" should make a nice clean up pass on the sides and leave a nice finish as well. Remember that you are only cutting on one side of the hole, so you only move ut 1/2 the distance that you need.

[GlennW]

Try to keep from re-cutting the chips by using air or a vacuum to keep them clear.

That was pretty much the short, basic, version above as I was running the grill cooking some dinner and ran out of time.

If you need a bit mere info, just ask!

[Vern2]

Glenn,

Thanks! I thought I would need a rotary table some day, it's just been collecting dust. Found some magnetics on ebay, have not a clue how many or what size I need. So you see, this may not be the first mounting plate I may have to make, .

My old shop would not let me put in a 2x2 plasma table, no room. The table build is on going, enjoy. http://www.enichesoftware.com/plasma/index.htm

It's been a while sense I've been around. I actually started to organize things into a real shop.

The heat pump is not installed and still working on 3'x4' setup welding table. Everything else is done (compressed air 110v, 220v out lets, and tools are in place.)


man cave

[Vern2]

Drilling pockets for magnets is not a problem. It's making tapered guide pins with matching guide holes. When torch is attached, it aligns it's self for next cut path.

I'm thinking the guide pins have to be very short. Why? When torch hits an obstruction, the guides, have to become offset a small amount for a gap to form with magnetics. This allows torch to fall away from torch mounting and stop any damage to machine during torch travel.

Looks like I'll need to make a jig to hold both parts for mounting on rotary table. Setup rotary table for locating three holes in drawing.

Mount first plate, do this...
Using a drill chuck:
1) Drill three tapered holes.
a) Use tapered Burs?
b) Use 6 flute Countersink?
c) Use 60 degree Drill countersinks?

Change to second plate.

2) Drill three straight holes for taping. (for mounting tapered pins)

Do these operations using a jig to build two matching 6061 plates for mounting.

Need to know the process or tools needed.

Thank you for helping.

Vern

[GlennW]

Use steel balls rather than pins.

Set them in epoxy in the one plate so that only half of the ball is exposed. Drills holes in the other plate to match the diameter of the ball.

The balls will locate the plate when the magnets grip and any side load such as the torch hitting an obstruction will let the plate slip right over the balls and come loose.

[Vern2]

Use steel balls rather than pins.

Set them in epoxy in the one plate so that only half of the ball is exposed. Drills holes in the other plate to match the diameter of the ball.

The balls will locate the plate when the magnets grip and any side load such as the torch hitting an obstruction will let the plate slip right over the balls and come loose.

Should I try to create pocket using special kind of end mill or just drill holes and use a 1/2" steel ball?
1) 31/64" drill for half of ball set in epoxy.
2) 32/64" drill for socket



Note:
1) I'm ready for a cool magnetic mounting.
2) If this works good it may become a kit for sale.

Vern

[GlennW]

I'd just use a drill and drill to a depth so that the ball seats in the hole with half it's diameter exposed.

[sjames]

im actually working on almost the exact same project. but for a machine torch, so im not re-using the supplied bracket.

I made the magnetic holder a few weeks ago and tried to use just that, but the pressure from the torch cable was too much for the magnets alone to keep in position, i made it work as is, but it will only break away in one direction, if it hit something while moving on the Y axis, it would not.

so I ordered some ball nose spring plungers and will incorporate those, hopefully this weekend.

[Vern2]

sjames,

I just cleaned up rotary table and found t bolts for it. Have to figure the radius and pattern yet.

What size balls have you tried? How many magnets? I'm not saying it's going to be easy. Looks like I'll be making a few before the right combination is hit.

Was thinking 1/2" ball, but the offset seems it would be to great for it would work. Was thinking small offset would be better, then play with number or size of magnets.

Found this http://www.pirate4x4.com/forum/torchmat ... -kits.html

Do you know about Snap -n- cut? http://www.snapncut.com/

[sjames]

Im only using three 1/2" magnets, which is plenty to hold it to the backer plate, but not enough to keep it from rotating under strain from the cable, you may need more magnets, the hand torch sticks out quite a bit farther, so more leverage to deal with.

I didn't need a fancy layout because I made a steel plate to mount in the carriage, so the magnets dont need to line up with anything. but I will have to do something to get the spring balls to line up properly with the pockets and have the torch end up square to the work.

I ordered 2 sets of ball plungers, 1 set with a .26 dia ball and a set with a .51 ball.

http://www.mcmaster.com/#catalog/119/3343/=mz5tdh
Flush-Mount Ball-Nose Spring Plungers

i haven't decided which ones to use yet, but I suspect ill try the smaller ones first.

I may start over from scratch, i think i can shave off some more material, and offset my torch some more and get a little more usable table travel out of it.(which seems to be the only disadvantage of running a machine torch)

Ill take a couple pics this weekend

I have heard of snap-n-cut, and I almost ordered one, but I had most of the stuff needed to make one, so I went that route instead.

[Vern2]

sjames,

Your right the magnets do not have to be aligned. The three balls do need to be drilled in both plates with rotary table. One with balls half into aluminum plate, other half for alignment of torch 90 degrees to metal, every time it gets knocked off.

Thanks for the link, here's one for you.

Link for ball buttons. http://www.mcmaster.com/#ball-buttons/=mzazzs

I think Keith is using spring balls, take a look.

http://youtu.be/u_5VVVgN7o4

http://youtu.be/MxeCktZBqnE